That's my interpretation of the creative process behind fiction and invention also. You take a familiar concept in your mind and mutate it with the goal of either making something more efficient or effective (invention) or of creating engaging narrative (fiction).

Depends on how unique the thought needs to be. You could simply count up from 0 and eventually you'd encounter a number you'd never thought of before, like 145,398, which I'm pretty sure is a number I've never thought about. You could do this forever and still be having technically unique thoughts.

The problem, I think, is that all thoughts seem to be a product of previous thoughts. Totally new thoughts are driven by external stimuli. We can, however, mutate an existing thought into a new one. I think this would be my process, take a common thought and change one aspect of it at a time until it's unrecognizable.

Things that work for me, not necessarily recommendations:

• Mindfulness practices
• Always be a little bit too busy for comfort, keeps you from dwelling on things
• Smoke; weed or tobacco, both help
• Deliberately cultivate positive self-talk, don't just uncritically accept whatever you mind tells you